Low muscle mass or poor muscle performance are characteristics of many diseases and conditions.
Muscle-related pathological conditions include myopathies, neuromuscular diseases, such as Duchenne muscular dystrophy, acute sarcopenia, for example muscle atrophy and/or cachexia, for example associated with burns, bed rest, limb immobilization, or major thoracic, abdominal, neck and/or orthopedic surgery. Age-related muscle-loss is an especially prevalent condition. Cachexia due to prolonged immobilization or other diseases, for example cancer, are other conditions that are often characterised by poor muscle performance.
Good muscle performance is important for effective living at all stages of life in healthy individuals as well as in those individuals suffering from a disease, especially the elderly. Improved muscle performance is of particular interest to athletes. For example an increase in muscular contraction strength, increase in amplitude of muscle contraction, or shortening of muscle reaction time between stimulation and contraction are all of benefit to individuals, especially athletes.
In severe cases of muscular atrophy, an anabolic steroid such as methandrostenolone is administered to patients to assist in the curative process. Such drugs can have numerous side-effects so their long-term use is preferably avoided.
Since the absence of muscle-building amino acids can contribute to muscle wasting, amino acid therapy is beneficial for regenerating damaged or atrophied muscle tissue, and for building muscle mass. The branched-chain amino acids or BCAAs (leucine, isoleucine, and valine) are important to this process, in addition to lysine and other amino acids.
Protein-containing nutritional products are available that are specifically formulated to increase muscle mass, improve muscle performance and/or reduce muscle wasting in elderly or hospitalised individuals. In general, it is necessary to exercise regularly for the desired improvements to be achieved.